in www.aaws.nl/images/stories/DST_overview_concept.pdf
it says Bamboos straws to strengthen...

Hi Detlev,
I am not sure if I got it right, but from the drawings it looks like the whole tank is underground like a classical septic tank. So I think you would also need a structure (concrete or brickwork) to maintain stability of the underground tank, wouldn't you?
What I have seen a lot in Vietnam are biogas digestors made out of plastic foils, of course they were used mostly for animal manure, but toilets can be connected as well: www.fao.org/ag/aga/agap/frg/Recycle/biodig/manual.htm
Regards, Florian

FYI: The DST proposes a smart and effective alternative for the presentconcrete-iron septic tank construction. The DST is designed using strong and sturdy foils to construct a double tank system. Concrete is no longer needed.


www.aaws.nl/images/stories/DST_overview_concept.pdf

In the same way small ABRs could be constructed without concrete...

Regards,
Detlef